Inertia type pump or compressor



Aug. 3, 1965 A. E. ROBERTSON INERTIA TYPE PUMP OR COMPRESSOR 2 Sheets-Sheet 1 Filed Dec. 5, 1965 INVENTOR. ANTHONY E. ROBERTSON AGENT Aug. 3, 1965 A. E. ROBERTSON INERTIA TYPE PUMP OR COMPRESSOR Filed Dec. 5, 1963 2 Sheets-Sheet 2 INVENTOR ANTHONY E. RBERTSON AGENT United States Patent O 3,198,425 INERTHA TYPE PUMP QR CGMPRESSQR Anthony E. Rohertson, Belle Mead, NJ., assigner to llngersoli-Rand Company, New York, NSY., a corporation of New liersey Filed Dec. 5, '1963, Ser. No. 328,399 12 Claims. (Cl. 2230-174) The present invention relates generally to pumps or compressors, and more particularly to pumps or compressors of the inertia reciprocating type.

Inertia, or free piston type pumps or compressors are not new, typical arrangements thereof being shown in U.S. Patents 1,715,638, granted June 4, 1929 to C. H. Braselton et al.; 1,769,799, granted July 1, 1930 to F. B. MacLaren; ,and 2,839,237, granted June 17, 1958 to H. Dolz.

An object of the present invention is to provide an inertia type pump or compressor that is of simple and rugged construction, and not readily lsubject: to malfunction.

Another object of the present invention is to provide 'an inertia type pump -or compressor vhaving .a single free piston and discharging pressure tiuid during bot-h strokes of each operating cycle. And another object of the present invention is .to provide an inertia type pump or compressor particularly `adapted for use where leakage of the tluid being pumped or compressed cannot be tolerated.

And still another object of the present invention is to provide tan inertia type pump or compressor yadapted for use where seepage of lubricant into the pump or compressor chamber cannot be tolerated.

This invention contemplates a compres-sor comprising a cylinder adapted to be mounted for reciprocati-on; a piston slidably disposed in the cylinder dividing the area therein into two compression chambers; the piston and cylinder reciprocating yaxially relative to one another when the cylinder is reciprocated .to alternately increase .and decrease the volume of each compression chamber, the volume of 4one compression chamber simultaneously increasing as the volume yof the other compression chamber is decreasing; the cylinder having an inlet chamber and tan outlet chamber at each end adjacent each compression chamber; normally closed valve means disposed in the ends of the cylinder each passing the compressedruid from a compression chamber reducing in volume to the ladjacent outlet chamber and passing uid to be compressed lfrom an inlet chamber to lthe adjacent compression chamber increasing in volume; manifold means in communication with the chambers at the ends of the cylinder providing a flow path between the inlet chambers and another flow path between the outlet chambers; a pair of conduit means each connected at one end to `an end of the cylinder .and held against movement at its other end; one of the conduit means being in communication with an inlet chamber and adapted to receive uid to be compressed; and the other of the conduit means being in'communication with an outlet chamber to provide .a delivery connection for compressed huid.

The foregoing and other objects and advantages will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein several embodiments of the invention a-re illustrated by way of example. It is to be expressly understood, however, that the drawings .are for illustration purposes only and are not to be construed as deiining the limit-s of the invention.

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FIGURE 2 .is a sectional View taken on line 2-2 of FIGURE 1,

FIGURE 3 is .a diagrammatic, elevational view, with portions thereof broken away, of one end Iof a compressor made in accordance withV the present invention illustrating moditicati-ons of the compressor of FIGURE 1, and

FIGURE 4 is Va sectional view similar to FIGURE 2 taken online 4 4 of FIGURE 3.

Inasmuch as the drawings are diagrammatic illust-rations, the manner of makingysealed connections of parts is not shown or described as they form no part of the invention. It should be understood that sealed connections can be made in any conventional manner well known in `the art. It should be further understood that compress-or is used hereinaiiter in its generic sense as pertaining to, both, pumps and compressors, depending upon the iluid being handled.

A compressor 10, as shown in FIGURES 1 and 2 has a base or base frame 11 with .a pair of `spaced openings 12throug-h the top thereof. A crank shaft 14 is mounted in the base `11 for rotation by .a motor (not shown). A pair of crank arms 13 extend through openings 12 and are connected attheir bottom ends to crank shaft 14 to provide reciprooation to the compressor 1t? when the crank VFIGURE 1 is a diagrammatic, elevational View of a i is not intended to define limits of the present invention.V

A cylinder assembly 20 is slidably mounted on tracks 17 .for reciprocation when crank shaft 14 is rotated Iand is comprised of a cylinder 30 that is closed .at its ends by. -a base plate 21 and a head plate 26. Base .plate 21 has a plurality of bearings 22 each engaging one of the tracks 17, and `a pair of hinges 23 to which the ends of arms 13, remote from crank shaft 14, `are attached. The cylinder side of plate 21 has .a diametrically disposed iange 24 that sealingly engages the cylinder 30 at its ends. Plate -21 also has a port 25 to provide a flow path therethrough on one side of liange 24.

Head plate 26 has bearings 27 corresponding to bearings 22, -a ange 28 corresponding and disposed parallel to iiange `24, and a port 29 to provide a How path therethrough on .the side of flanges 24 and 28 opposite from port 25.

A tiexible, coiled conduit 15 is connected at one end to plate 21 in communi-cation with port 25, `and is iiXedly supported' by base frame 11. Similarly, a flexible, coiled conduit 18 is connected at one end to plate 26 in communication with port 29, and is xedly supported at its other end 'by head frame 16. Conduit 15 and port 25 have been arbitrarily chosen as providing the inlet dow path t-o the cylinder assembly 20. Thus, -conduit 1S and port 29 provide the outlet flow path. The inlet or Voutlet flow path as described above, may be disposed at either end of compressor l1t) las long las compatible valving is provided, as will be described hereinafter.

A plate or cup 31 ixedly disposed in the base end of cylinder assembly 20 sealingly engages flange 24 and, at its periphery, the cylinder 3G to provide a wall spaced from plate 21 defining, therebetween, an inlet chamber 34 disposed on one side of flange 24, in communication with port 25, and an outlet chamber 35 disposed on the opposite side of the ilange.V Wall 31 has a pair of spaced ports 32 and 33 in communication with chambers 34 and 35, respectively. A pair of valves 36 and 37 are provided, in this instance, connected to wall 31. Valve y 36 prevents iiow of iluid into inlet chamber 34 through port 32 while valve 37 prevents flow out of chamber 35 through port 33.

A plate or cup 41, similar to plate 31, is disposed in the head end of cylinder assembly 20 and sealingly engages flange 2S and, at its periphery, the cylinder 3f) to provide a wall spaced from plate 26 defining, therebetween, an inlet chamber 44 disposed on one side of flange 23 and an outlet chamber 45 disposed on the other side of the angc. Plate 41 has a pair of spaced ports 42 and 43 corresponding to ports 32 and 33, respectively, of plate 31, and valves 46 and 47 are provided to correspond to respective valves 36 and 37 at the other end of cylinder assembly 2t). Therefore, it will be noted, that both inlet chambers 34 and 44 are disposed on one side of cylinder assembly 2t) or flanges 24 and 29, and both outlet chambers 35 and 45 are disposed on the opposite side. A pair of manifold conduits 38 and 3 are provided on opposite sides of cylinder assembly 20 both ends of each being connected to and extending through cylinder E@ to provide communication between inlet chambers 34 and 44 through manifold 38, and between outlet chambers 35 and 45 through manifold 39.

A piston E@ is slidably disposed in cylinder 30 dividing theV area therein into a compression chamber 51 adjacent wall 31 and a second compression chamber 52 adjacent wall d1. Relative axial movement between piston 5) and cylinder 30 varies the volumes of compression chambers 51. and 52, in a reverse sense, so when pressure tiuid is being discharged from one of such chambers, inlet Huid is being provided to the other.

Although piston Sti may be free to float, it has been found preferable, in most instances, to provide a pair of axially disposed springs 53 and 54 disposed in chambers S1 and 52, respectively, acting in opposition to one another for urging piston 54B to a central position between walls 31 and i1 when the compressor is not operating. It should be noted that spring 53 should be slightly stronger than spring 54 to compenate for the weight of piston 5t) when compressor reciprocation is in a vertical plane, as shown. It should be understood that, while not showna compressor 1t) may be positioned so reciprocation occurs horizontally. Y

In operation, crank shaft 14 is rotated to reciprocate cylinder assembly 2t, on tracks 17. At start-up, piston 5% will tend to move in unison with cylinder assembly 2t). However, as the operating speed increases, increasing the reciprocation frequency of piston assembly 2t), reciprocation of piston 50 reduces resulting in increasing relative movement between piston Sti and cylinder assembly 29 or increasing compression action by the machine. When the reciprocation frequency reaches the natural frequency of the piston 59, immersed in the iiuid being compressed and in the presence of friction with the force-s of compression and springs 53 and 54, the piston will assume a relatively fixed position resulting in maximum relative movement between piston 50 and cylinder assembly 36, or maximum compression actions.

it should be understood that during operation of compressor 19 valves 3e and 46 permit only inlet flow alternately to respectivechambers 51 and 52. Simultaneously, valves 37 and 47, permit only outlet or discharge flow alternately from such chambers. Thus while uid is being compressed and discharged from one of the chambers 51 or S2, the other of the chambers is filling with fluid to be compressed.

lt should also be realized that there are no portions of the flow path forming moving connections .subject to leakage, and the inlet and outlet conduits 15 and 18 yare arranged for minimal movement to preclude fatigue failure.

Various modifications may be made to compressor 10 Within the scope of the present invention, as shown in the modified compressor 16A of FIGURES 3 and 4. Modified parts of the modified compressor NA are identied by the same numbers identifying correspondingV compressor fr@ but include a suffix A.

Accordingly, modified compressor 10A has only two tracks 17 connected at their ends to a base frame (not shown) and a modified head frame 16A. For installation where minimal leakage may be tolerated, a tube-in-tube arrangement may replace the coiled tiexible conduits 15 and 1S. Referring to FGURE 3, only one is shown by way of example wherein an axially disposed conduit 19 is connected to modified end plate ZA 'in communication with outlet port 29A; the other end normally having a seal arrangement (not shown) receiving the end of a coaxial tube or conduit 18A supported by frame 16A. Thus, as the modified cylinder assembly ZtiA reciprocates, conduit i9 moves axially on conduit lA.

Finally, modified cylinder assembly ZA has a modified cylinder 39A which includes cored passages 38A and 39A which correspond to the inlet and outlet manifold conduits 38 and lt should now be readily understood that an inertia type compressor is provided embodying a single free floating piston which discharges pressure fiuid during both strokes of each cycle of reciprocation and provides a leakproof device.

Although several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

I claim:

1. A compressorcomprising:

`(a) a cylinder adapted .to be mounted for reciprocation;

(b) a piston slidably disposed in the cylinder dividing the area Vtherein into two compression chambers;

(c) ythe piston and cylinder reciprocating axially relative to one another when the cylinder is reciprocated to alternately increase and decrease the volume of each compression chamber, the volume of one compression chamber simultaneously increasing as the volume of the other compression chamber is decreas- 111s;

(d) the cylinder having an inlet chamber and an outlet chamber at each end adjacent each compression chamber;

(e) normally closed valve means disposed in the ends of the cylinder each passing compressed fluid from a compression chamber reducing in volume to the adjacent outlet chamber and passing fluid to be compressed from an inlet chamber to the adjacent compression chamber increasing in volume;

(f) manifold means in communication with the charnber at the ends of the cylinder providing a ow path between the inlet chambers and another fiow path between the outlet chambers;

(g) a pair of conduit means each connected at one end to an end of the cylinder and held against movement at its other end;

(h) one of the conduit means being in communication with an inlet chamber and adapted to receive fiuid to be compressed; and

(i) the other of the conduit means being in communication with an outlet chamber to provide a delivery connection for compressed fluid.

2. A compressor in accordance with claim 1 and:

(a) a pair of springs each disposed in one of the compression chambers acting in opposition to the other 'and together biasing the piston away from Ithe ends of the cylinder.

3. A compressor in accordance with claim 1, wherein each of the conduit means comprises:

(a) a coiled flexible conduit with its end held against movement being spaced axially from the end of the cylinder to which its one end is connected.

4. A compressor in accordance wit-h claim 1, wherein each of the conduit means comprises:

(a) a pair of axially disposed tube members, one extending intro the other and having seal means therebetween; and

(b) one of the tube members being held against movement and the other being connected to the cylinder |and movable axially relative to the xed tube member when the cylinder is reciprocated.

5. A compressor comprising:

(a) a frame;

'(b) ya cylinder .slidable on the frame;

(c) means mounted on frame being connected to the cylinder `to reciprocate the cylinder on the frame;

(d) a piston slidably disposed in the cylinder dividing the area therein into two compression chambers;

(e) the piston and cylinder reciprocating axially relative to one another when the cylinder is reciprocated to alternately increase and decrease the volume of each compression chamber, the volume of one compression chamber simultaneously increasing as the volume of the other compression chamber is decreasmg;

I(f) the cylinder having an inlet chamber and an outlet chamber at each end adjacent each compression chamber;

(g) normally closed valve means disposed in the ends of the cylinder each passing compressed fluid from a compression chamber reducing in volume to the adjacent outlet chamber and passing iluid to be compressed from an inlet chamber to the adjacent compression chamber increasing in volume;

(h) manifold means in communication with the chambers at the ends .of the cylinder providing a ow path between the inlet chambers and another ow path 'between the outlet chambers;

(i) a pair of conduit means each connected at one end to an end `of the cylinder and held against movement at its other end;

I(j) one of .the conduit means being in communication with an inlet chamber and adapted to receive fluid to be compressed; and

(k) the other of the conduit means being in communication with an outlet chamber to provide a delivery connection for compressed duid.

6. A compressor in accord-ance with claim 5, and;

=(a) a pair of springs each disposed in one of the compression chambers aoting in opposition to the other and together biasing the piston away from the ends of the cylinder.

7. A compressor in accordance with claim 5, wherein each of the conduit means comprises:

(a) a coiled exible conduit with its end held against movement being connected to the frame axially spaced from the end of the cylinder to which its one end is connected.

'8. A compressor in accordance with claim 5, wherein each of the conduit means comprises:

(a) a pair of axially disposed tube members one extending into the other and having seal means therebetween; and

(b) one of the tube members being connected to the frame and held against movement thereby, and the other being the end connected to the cylinder.

9. A compressor comprising:

(a) a frame;

(b) a cylinder slidable on the frame and having a pair of walls closing the ends thereof;

(c) means mounted on frame being connected to the Cylinder to reciprocate the cylinder on the frame;

(d) a pair of `spaced walls disposed in the cylinder eac-h being spaced from one of the end walls;I

(e) :a piston slidably disposed in the cylinder dividing the space between the pair of spaced walls into two compression chambers;

(f) the piston and cylinder reciprocating axially relative -to one another when the cylinder is reciprocated -to alternately increase and decrease the volume of each compression chamber, the volume of one compression chamber simultaneously increasing as the volume ofthe other compression chamber is decreasme;

( g) the cylinder having a pair of substantially diametrical walls each disposed between one of the pair of spaced walls and the end wall from which it is spaced providing an inlet chamber and an outlet chamber at each end of the cylinder adjacent each of the compression chambers;

(h) normally closed valve means operatively associlated with each of the pair of spaced walls for pass- Ilng compressed fluid from a compression chamber reducing in volume to the adjacent outlet chamber and passing uid to be compressed from an inlet chamber to the adjacent compression chamber increasing in volume;

`(i) manifold means in communication with the chambers at the ends of the cylinder providing a ow path bet-Ween the inlet chambers and another flow path between the outlet chambers;

(j) a pair of conduit means each connected at one end -to an end of the cylinder and held against movement -at its other end;

(k) `one of the conduit means being in communication `with an inlet chamber and adapted to receive fluid to be compressed; and

(l) the other of the conduit means being in communi-V cation with an outlet chamber to provide a delivery 'connection for compressed tluid.

10. A compressor in accordance with claim 9, and:

(-a) la pair 4of springs each disposed in one of the compression chambers acting in opposition to the other and together biasing the piston away from the eIldS of the cylinder.

11. A compressor in accordance with claim 9, wherein each of the conduit means comprises:

(a) a coiled exible conduit with its end held against movement being connected to the frame axially `spaced from the end of the cylinder to which its one end is connected.

y12. A compressor in accordance with claim 9, wherein each of the conduit means comprises:

(a) a pair of axially disposed tube members, one eX- tending into the other and having seal means therebetween; iand (b) one of the tube members being connected to the frame and held against movement thereby, and the other, being the end connected to the cylinder.

References Cited by the Examiner UNITED STATES PATENTS y1,831,993 `11/31 Braselton et al 10S-208 2,839,237 6/58 Dolz 230-174 X 3,003,428 10/61 Christenson 103--175 DONLEY J. STOCKING, Primary Examiner. 

1. A COMPRESSOR COMPRISING: (A) A CYLINDER ADAPTED TO BE MOUNTED FOR RECIPROCATION; (B) A PISTON SLIDABLY DISPOSED IN THE CYLINDER DIVIDING THE AREA THEREIN INTO TWO COMPRESSION CHAMBERS; (C) THE PISTON AND CYLINDER RECIPROCATING AXIALLY RELATIVE TO ONE ANOTHER WHEN THE CYLINDER IS RECIPROCATED TO ALTERNATELY INCREASE AND DECREASE THE VOLUME OF EACH COMPRESSION CHAMBER, THE VOLUME OF ONE COMPRESSION CHAMBER SIMULTANEOUSLY INCREASING AS THE VOLUME OF THE OTHER COMPRESSION CHAMBER IS DECREASING; (D) THE CYLINDER HAVNG AN INLET CHAMBER AND AN OUTLET CHAMBER AT EACH END ADJACENT EACH COMPRESSION CHAMBER; (E) NORMALLY CLOSED VALVE MEANS DISPOSED IN THE ENDS OF THE CYLINDER EACH PASSING COMPRESSED FLUID FROM A COMPRESSION CHAMBER REDUCING IN VOLUME TO THE ADJACENT OUTLET CHAMBR AND PASSING FLUID TO BE COMPRESSED FROM AN INLET CHAMBER TO THE ADJACENT COMPRESSION CHAMBR INCREASING IN VOLUME; (F) MANIFOLD MEANS IN COMMUNICATION WITH THE CHAMBER AT THE ENDS OF THE CYLINDER PROVIDING A FLOW PATH BETWEEN THE INLET CHAMBERS AND ANOTHER FLOW PATH BETWEEN THE OUTLET CHAMBERS; 